1. Field of the Invention
The present invention relates generally to the field of optical imaging and specifically to a system for generation of three-dimensional real images.
2. Description of the Related Art
One of the important attempts at producing a three-dimensional real image generation system is Elings, U.S. Pat. Ser. No. 3,647,284, which features two opposing concave mirrors having a common optical axis. One of the mirrors presents an aperture. The object is placed close to the opposite facing mirror to generate a real image beyond the aperture. The Elings system is somewhat restrictive in use because of restrictions in where the object may be placed. In particular, it must be placed fairly closely to the mirror not having an aperture. Also, it has the drawback of not being easy to manufacture since construction of the one mirror requires the inclusion of an aperture. This of course also adds to the cost of manufacturing.
Welck, U.S. Pat. Ser. No. 4,802,750, features mirrors of paraboloid-of-revolution shape, the two mirrors configured to present an associated real object zone to which the object must be placed for optimal use. There is also associated a real image zone in which vicinity the real image is perceived. The Welck system also has restrictions as to object placement since the object must be placed in a relatively constricted spatial area. Also, due to the specific shape of the mirrors required (i.e. mirrors of paraboloid-of-revolution shape) this adds to the cost and difficulty of manufacture.
A third system in this field is the Summer system, U.S. Pat Ser. No. 5,311,357. Two concave mirrors are placed at an appropriate acute angle so that when an object is placed inside the focal length of the first mirror a real-image is generated. Here again, the object is greatly restricted as to the area in which it can be placed relative to the first mirror and also the size of the object that can be utilized by the system is restricted because of the relative closeness of the object to the first mirror. The Summer patent refers to a first mirror and second mirror in the sense that the rays emanating from the object first strike mirror two and then mirror one. It should be noted that the reverse terminology is used herein with reference to the present invention and all other Systems, including Summer.
Important prior systems in this field have spatial limitations in terms of object placement. That is to say, the object must be placed in a relatively restricted zone, typically in close proximity to the first mirror for optimal performance. For example, in the Summer system, the object must be placed within the focal length of the first mirror. Other systems may have other similar types of limitations all of which, as discussed above, tend to restrict the utilization of the system since objects cannot be placed farther away from the mirrors. Also many of the systems in this field have ease and cost of manufacture issues so that they are not readily commercially manufacturable both for reasons of construction and of cost.
The improved optical apparatus and system of the present invention produces a three-dimensional real image of an object. The apparatus includes a support member, a first concave reflective surface affixed to the support member and having an associated focal length, and a second concave reflective surface affixed to the support member. The first concave reflective surface and the second concave reflective surface are placed in substantially fixed spatial relationship to each other to define an acute angle. When an object is appropriately placed further from the first concave reflective surface than the focal length thereof, the apparatus produces a realistic three-dimensional real image of the object.
In preferred embodiments the first and second reflective surfaces are spherical mirrors, the support member includes an object base suitable for securely positioning the object and the support member further includes an outer housing such that the object, the light source, the first mirror and the second mirror are not externally observable by a viewer.
In alternative embodiments the object can independently generate light (e.g. a display device). In other alternative embodiments, the first and second reflective surfaces are in substantially fixed, spatially parallel relationship.